Pharmacokinetic and pharmacodynamic interactions of echinacea and policosanol with warfarin in healthy subjects.

Aims: This study investigated the pharmacokinetic and pharmacodynamic interactions of echinacea and policosanol with warfarin in healthy subjects.

Methods: This was an open-label, randomized, three-treatment, cross-over, clinical trial in healthy male subjects (n= 12) of known CYP2C9 and VKORC1 genotype who received a single oral dose of warfarin alone or after 2 weeks of pre-treatment with each herbal medicine at recommended doses. Pharmacodynamic (INR, platelet activity) and pharmacokinetic (warfarin enantiomer concentrations) end points were evaluated.